Stool for dentists

ABSTRACT

947,849. Hydraulically adjustable seats. VACUDENT MANUFACTURING CO. Oct. 12, 1962 [Oct. 13, 1961 (2); July 3, 1962], No. 38738/62. Heading B8J. [Also in Division A4] A stool comprises a platform base 13, a seat 10, extendible and retractable post structure 11, 12 rising from the base centrally thereof and supporting the seat 10, power means for extending the post to raise the seat, means such as a valve 34 controlling operation of the power means, and means for actuating the control means, the actuating means having a foot-operated portion 44 at least partially surrounding the post structure 11, 12 above the surface of the base 13. The post structure consists of a post 11 and tube 12 which together form an hydraulic assembly. A sleeve 15 is secured to the upper end of the tube 12. As shown in Fig. 4, the footoperated part of the actuating means consists of a ring 44 encircling the post structure. The actuating means also consists of a lever comprising a pair of rods 45 depending slidably through the base 13 from the ring 44, a bearing ring 47 slidable along the lower end of the post structure (Fig. 5) and a working arm 48 projecting from the ring 47. The arm 48 is secured to another lever arm 49 provided as part of valve 34 and pivoted at 50 to operate a spring-loaded plunger 35. The valve 34 is opened by pressure on the ring 44. This permits entrapped compressed air in a reservoir 32 to expand and force hydraulic fluid from this reservoir 32 into tube 12 to raise the seat 10 when the user takes his weight off the seat. A non-return valve 37 prevents fluid flow in the cylinder-reservoir direction. A bleeder passage 51 provides for gradual return of fluid to the reservoir 32 and thus a gradual lowering of the seat under the weight of the user when pressure is applied to the foot ring 44. The post is made in two parts 11, 11-1 so that the seat 10 can be raised independently of the power system. An abdominal rest 17 is provided which may be adjusted vertically, horizontally and rotatably relatively to the seat 10 by means of members 23, 21 and 29 respectively.

1964 E. o. THOMPSON ETAL 3,145,053

STOOL FOR DENTISTS Filed Oct. 15, 1961 INVENTORS ELBERT 0. THOMPSON DEANH. HALE fit ATTORNEYS United States Patent 3,145,053 STUGL FOR DENTISTSElbert 0. Thompson, Salt Lake City, and Dean H. Hale, Logan, Utah,assignors to Vacudent Manufacturing Company, Salt Lake (Iity, Utah, acorporation of Utah Filed Get. 13, 1961, Ser. No. 144,862 4 tjlaims.(Cl. 297--383) This invention relates to seating structures, andparticularly to stools for special purposes.

The invention is concerned primarily with providing a stool for dentistsand dental assistants to be used while working on or administering todental patients seated in a dental operating chair, although many otheruses are possible.

Dentists and dental assistants normally stand while working on oradministering to a patient in the dental chair. However, the necessityof bending over and peering into the mouth of a patient imposesconsiderable strain on the body and results in fatigue and often inmuscular pains of one kind or another.

While seating of the dentist during his work has been proposedheretofore and stools have been provided for this purpose, the needs ofa dentist and a dental assistant are such that stools of ordinaryconstruction encumber more than they aid.

Principal objects in the making of the present invention were to provideeffective and comfortable support for the waist as the upper trunk ofthe body is cantilevered forwardly toward the patient from a seatedposition; to provide this in a manner adaptable to the body characteristics of various users of the stool, to provide for easily andpositively locking adjustable components in their adjusted positions; toenable a short person, usually the dental assistant, to sit comfortablyand to maneuver effectively, even though his or her feet do not reachthe floor when seated; and to provide all of the above with streamlinedand pleasing appearance as well as compactness, ease of handling, andminimum spacial encumbrance.

Features of the invention in the attainment of these objects are theprovision of stool structure supporting a seat of circular stoolformation, and an abdominal body rest of curved strip formation adaptedto be mounted above the seat in an adjustable substantially cantileveredarrangement with respect to a supporting post disposed near thecircumference of the seat. The curvature of the body rest largelyconforms to that of the stool, and the mounting arrangement ispreferably such that the rest may be adjusted more or less inwardlytoward the vertical axis of the stool to accommodate thin as well asmedium and stout individuals, such body rest retaining much of itscantilever arrangement with respect to the post even in its extremepositions of adjustment so that it will extend across the front of thewaist of a person seated on the stool and give effective support whensuch person leans forwardly to take care of the dental work at hand.

Other features are the provision of a platform-like base affordingeffective support for the feet, particularly when the user is so shortthat, when seated, his or her feet do not reach the floor, and theprovision for independent swiveling of the seat and body rest relativeto each other.

The particular power mechanism and cam locks shown are the soleinvention of Dean H. Hale and are separately covered by an applicationfor patent Serial No. 144,980 filed concurrently herewith.

A specific embodiment of the invention representing what is presentlyregarded as the best mode of carrying out the inventive concepts inactual practice is illustrated in the accompanying drawings.

In the drawings:

FIG. 1 represents an elevational View of the stool looking directlytoward the back of the post which supports the body rest;

FIG. 2, a top plan view, with a different adjustment of the body restbeing indicated by broken lines;

FIG. 3, a bottom plan view;

FIG. 4, a fragmentary view in vertical section taken on line 44 of FIG.1 and drawn to a larger scale, showing one of the cam locks in itslocked position; and

FIG. 5, a corresponding view, but showing the cam lock in its unlockedposition.

Referring to the drawings:

In the form illustrated, the stool comprises a circular seat 10supported in stool fashion at the upper end of a post 11, which risescentrally from a base 13 and depends centrally from the seat as part ofan extendible and retractable hydraulic assembly (not shown) mounted insuch base.

Base 13 is platform-like and hollow, being maneuverably supported bycasters 14. There must be at least three castors for stability, as isquite apparent, but preferably there are five, so that, regardless ofsurface irregularities in the floor unevenness, there will always be atleast a three-point support for the stool with consequent stability atall times during use. The platform character of this base providing asubstantially unbroken expanse of supporting surface coupled with thefact that its diameter significantly exceeds that of the seat 10 so thatits periphery extends outwardly beyond the periphery of the seat,enables a person seated on such seat to comfortably and effectively resthis or her feet off the floor when found desirable.

For added strength and to facilitate lubrication, a sleeve 15 extendsdown to the base 13 as a tube housing, where it is secured as bywelding. A ring of oil-impregnated felt (not shown) wipes oil onto thesurface of post 11 as it rises and descends relative thereto.

In order to provide support for the trunk of the body of a dentist ordental assistant when working from a seated position and leaningoutwardly from the seat 10, an abdominal rest 17 is provided in upwardlyspaced relationship with the seat. It is supported in what isessentially cantilever fashion from a post 18, which is preferably abroad and rigid bar or strip of some such material as steel or aluminumrising above the seat near the circumference thereof.

Body rest 17 is of broad strip formation in the sense that it is widebut relatively elongate, so as to provide comfortable and effectivesupport for the body at or near the waist. It and seat 10 are preferablycushioned with foam rubber or the like and upholstered with a washableplastic sheet material.

While in some instances it may be desirable to construct the stool withthe body rest permanently fixed to its supporting post, in theillustrated construction rest 17 is adjustably positioned relative topost 18 so as to accommodate thin as well as stout persons. In anyevent, the rest is largely curved in conformity with the seat and ispositioned so that its width extends vertically and so that its lengthextends horizontally in cantilever fashion from one side of the post.

To enable a person to easily move into and out of position on the seatwith respect to the body rest, such body rest preferably has itsopposite end portions deviating outwardly from the aforespecifiedcurvature, the end portion 17a nearest the supporting post 18advantageously being rectilinear or approximately so. Best results arehad when the circularly curved intermediate portion of the rest subtendsan angle of about For the purpose of adjustment, rest 17 is: providedwith a bracket arm 19, which extends from near the middle of such restbackwardly and outwardly along the back of one end portion of the rest,see particularly FIG. 2, and

enemas is firmly secured to post 18 by suitable releasable fasteningmeans, such as a unique cam lock 20 operable by hand lever 21 andconstructed as shown in detail in FIGS. 4 and 5. In turn, post 18 isfirmly but adjustably secured to the rest of the stool structure bymeans of a second cam lock 22, FIG. 1, operable by hand lever 23.

While cam lock 22 is illustrated in FIGS. 4 and 5, cam lock 20 is of thesame type. As shown, a slotted receptacle 24, FIGS. 4 and 5, defines athroughway for slidably receiving post 18 (bracket arm 19 in theinstance of cam lock 20). Extending across the interior of receptacle 24and journaled in the lateral walls thereof is a cam 25 in the form of arod whose cross section is circular, except for a sector face 26 whichis preferably provided with a continuation in the form of a protuberantlip 27 having a terminal face 27a at substantially right angles theretomerging into the otherwise cylindrical periphery of the rod along atangent.

The lever arm or operating handle 23 (21 in the instance of cam lock 20)is fixed to one end of the cam rod 25 perpendicularly to the sector face26 of such rod, so that, when such handle is turned up as shown in FIG.1 (inwardly in the instance of handle 21 of cam lock 20) a curvedportion of such rod exercises cam action against the opposing face ofpost 11 to frictionally lock it tightly against therewith opposing faceportions of receptacle 24.

When it is desired to adjust the height of body rest 17 relative to seat10, it is only necessary to throw handle 23 downwardly and outwardly tobring sector face 26 into parallel position with the' aforesaid opposingface of post 18, see FIG. 5. Lip 27 prevents over-ride and positivelyestablishes the unlocked position. Likewise with cam lock 20, it is onlynecessary to turn handle 21 clockwise to a position substantiallyperpendicular to bracket arm 19 in order to permit positional adjustmentof body rest 17 relative to its supporting post 18 and to seat 10.

Receptacle 24 of cam lock '22 is secured, as by welding, to the outerand upwardly turned end of a mounting bar 28, so that its throughway isdisposed vertically for slidably receiving post 18, while the receptacleof cam lock 20 is similarly secured to the upper end of post 18 with itsthroughway disposed horizontally for slidably receiving bracket arm 19.

Mounting bar 28 is secured, as by welding, to the upper end of post 11,and, in order to provide for independent swiveling movement of seat andbody rest 17 relative to each other, an anti-friction bearing 29, hasits upper race plate secured to the seat, as by bolts, and its lowerrace plate secured to mounting bar 28 and post 11, as by welding.

The mechanism, indicated 32-34, 37, 41, and 42, FIG. 3, for raising seat10, and coincidentally, body rest 17, is housed within hollow base 13and is operated by a foot pedal 31 which projects a convenient distancebeyond the outer periphery of the base, see FIGS. 1, 2, and 3, at alocation that is preferably diametrically opposite one of the castors14. In order that the person seated on the stool can easily locate suchfoot-pedal without looking down, it is preferred to permanently fix suchopposite castor against swiveling movement, as by driving a pin (notshown) through the castor shank and its holder.

The height of stool seat 10 is adjusted by pressing footpedal 31. It isnot intended that there be a lifting of a person seated on the stool,but, rather, that there be a powered lifting of the stool seat 10 alone,since this is all that is necessary from a practical standpoint. Thus,when the dentists or other person using the stool desires to alter hisworking position upwardly, he need merely step on the foot-pedal whileraising his body. The stool seat will closely follow until the pedal isreleased, whereupon a sitting position can be resumed without everhaving taken eyes or hands from the work in progress.

Whereas there is here illustrated and described a certain preferredconstruction which we presently regard as the best mode of carrying outour invention, it should be understood that various changes may be madewithout departing from the inventive concepts particularly pointed outand distinctly claimed herebelow.

We claim:

1. A stool particularly adapted for use by dentists and dentalassistants while working on dental patients, comprising, in combination:a maneuverable base structure; a substantially circular seat mounted onsaid base structure; a supporting post extending upwardly from and inadjacency to the periphery of said seat; means mounting said post forrevolution about the periphery of said seat; a trunk rest of strip-like,substantially curved configuration mounted cantilever fashion on saidpost and having its length extending substantially horizontallytherefrom; and means adjustably interconnecting said trunk rest and saidpost for lateral movement of the former relative to the latter, so thatthe degree of cantilever extension of said trunk' rest from said postcan be adjusted as desired.

2. The stool of claim 1 wherein the means adjustably connecting thetrunk rest and the post includes a bracket arm extending from the backof the trunk rest and extending longitudinally along approximatelyone-half of its length, and locking means for fastening the bracket armto the post in various positions of adjustment.

3. The stool of claim 1, wherein the base structure is of platformformation extending peripherally outwardly beyond the periphery of theseat and providing a substantially unbroken expanse of supportingsurface for the feet of the user, and wherein the seat is supported onsaid base structure by a center post extending upwardly therefrom.

4. The stool of claim 1, further including means interconnecting theseat and the base structure for rotation of said seat relative to saidbase.

References Cited in the file of this patent UNITED STATES PATENTS597,991 Lease Jan. 25, 1898 1,005,542 Harmer Oct. 10, 1911 1,976,449Lorenz Oct. 9, 1934 2,136,852 Knauth Nov. 15, 1938 2,244,650 Curran June3, 1941 2,400,630 Cramer May 21, 1946 2,620,863 Cooper 1 Dec. 9, 19522,935,120 Naus May 3, 1960 FOREIGN PATENTS 298,795 Great Britain Oct.18, 1928 880,237 Great Britain Oct. 17, 1958

1. A STOOL PARTICULARLY ADAPTED FOR USE BY DENTISTS AND DENTALASSISTANTS WHILE WORKING ON DENTAL PATIENTS, COMPRISING, IN COMBINATION:A MANEUVERABLE BASE STRUCTURE; A SUBSTANTIALLY CIRCULAR SEAT MOUNTED ONSAID BASE STRUCTURE; A SUPPORTING POST EXTENDING UPWARDLY FROM AND INADJACENCY TO THE PERIPHERY OF SAID SEAT; MEANS MOUNTING SAID POST FORREVOLUTION ABOUT THE PERIPHERY OF SAID SEAT; A TRUNK REST OF STRIP-LIKE,SUBSTANTIALLY CURVED CONFIGURATION MOUNTED CANTILEVER FASHION ON SAIDPOST AND HAVING ITS LENGTH EXTENDING SUBSTANTIALLY HORIZONTALLYTHEREFROM; AND MEANS ADJUSTABLY INTERCONNECTING SAID TRUNK REST AND SAIDPOST FOR LATERAL MOVEMENT OF THE FORMER RELATIVE TO THE LATTER, SO THATTHE DEGREE OF CANTILEVER EXTENSION OF SAID TRUNK REST FROM SAID POST CANBE ADJUSTED AS DESIRED.